Superhydrophilic amphiphilic copolymers and processes for making the same

Abstract

A superhydrophilic amphiphilic copolymer and process for making the superhydrophilic amphiphilic copolymer includes a low molecular weight polysaccharide modified with a hydrophobic reagent, such as substituted succinic anhydride. The superhydrophilic amphiphilic copolymer system generates stable foam for use in applications, such as healthcare formulations, with low irritation of the eyes and skin.

We claim:  
     
       1. A superhydrophilic amphiphilic copolymer comprising a starch-based or cellulose-based polysaccharide modified with one or more hydrophobic reagents wherein the one or more hydrophobic reagents comprises at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride;
 and wherein the superhydrophilic amphiphilic copolymer comprising the starch-based or cellulose-based polysaccharide modified with the one or more hydrophobic reagents comprising at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride has a weight average molecular weight that is less than about 200,000 and a solution viscosity of less than about 9 centipoise, 
 and wherein the superhydrophilic amphiphilic copolymer modified with the hydrophobic reagent comprising at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride is prepared by 
 forming an aqueous solution of the starch-based or cellulose-based polysaccharide in water by dissolving from about 25% to about 75% of the starch-based or cellulose-based polysaccharide in water, based on total weight of the aqueous solution, to produce the aqueous solution comprising the starch-based or cellulose-based polysaccharide, 
 adding the hydrophobic reagent comprising the at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride to the aqueous solution, and 
 reacting the hydrophobic reagent comprising the at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride with the starch-based or cellulose-based polysaccharide dissolved in the aqueous solution at a pH of 11.5 or greater to form an aqueous solution of the superhydrophilic amphiphilic copolymer comprising the starch-based or cellulose-based polysaccharide modified with the hydrophobic reagent comprising the at least one 3-chloro-2-hydroxypropylalkyldimethylammonium chloride. 
 
     
     
       2. The superhydrophilic amphiphilic copolymer of  claim 1 , wherein the polysaccharide is starch-based. 
     
     
       3. The superhydrophilic amphiphilic copolymer of  claim 2  wherein the polysaccharide is based on starch and is derived from potato or tapioca. 
     
     
       4. The superhydrophilic amphiphilic copolymer of  claim 3  wherein the polysaccharide is derived from waxy potato or waxy tapioca. 
     
     
       5. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the polysaccharide is cellulose-based. 
     
     
       6. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the polysaccharide has a weight average molecular weight of about 1,000 to about 100,000. 
     
     
       7. The superhydrophilic amphiphilic copolymer of  claim 6  wherein the weight average molecular weight of the polysaccharide is from about 1,000 to about 25,000. 
     
     
       8. The superhydrophilic amphiphilic copolymer of  claim 7  wherein the polysaccharide has a weight average molecular weight of from about 1,500 to about 15,000. 
     
     
       9. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the weight average molecular weight of the one or more hydrophobic reagents is about 220 or greater. 
     
     
       10. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the superhydrophilic amphiphilic copolymer has a turbidity of less than about 120 ntu of a 10% aqueous solution. 
     
     
       11. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the superhydrophilic amphiphilic copolymer forms a Max Foam Volume of about 400 mLs or greater when 1000 mls of a 0.5% aqueous solution of the polymeric surfactant is stirred at 1200 RPMs for 150 seconds. 
     
     
       12. The superhydrophilic amphiphilic copolymer of  claim 1  wherein the Foam Stability is about 40% or greater. 
     
     
       13. The superhydrophilic amphiphilic copolymer of  claim 1  having a mole percent of amphiphilic repeat units that is from about 1 to about 8.5. 
     
     
       14. The superhydrophilic amphiphilic copolymer of  claim 1  having a DP between 4 and about 500. 
     
     
       15. The superhydrophilic amphiphilic copolymer of  claim 1  having a Dynamic Surface Tension Reduction, t γ=55 , of less than about 120 seconds. 
     
     
       16. The superhydrophilic amphiphilic copolymer of  claim 1  having a PMOD % of less than about 90%.